Ghost Fitness/Omega-3/What are the potential side effects of taking omega-3 ethyl esters?
What are the potential side effects of taking omega-3 ethyl esters?
The short answer
Read off the prescription leaflet: common, dyspepsia and nausea; less common, taste disturbance, belching, abdominal pain and loose stools; a bleeding-time warning with anticoagulants at high doses; a small LDL rise at four grams; and the atrial fibrillation note. Then the form's own three: poor absorption without a fatty meal, worse reflux for many users than a triglyceride oil, and faster oxidation on the shelf.
- The leaflet, commondyspepsia and nausea
- The leaflet, less common and warnedtaste disturbance, belching, abdominal pain, loose stools; bleeding time with anticoagulants; a small LDL rise at four grams; the atrial fibrillation note
- The form's own threepoor absorption fasted; worse reflux for many; faster oxidation once opened
- The comparisona triglyceride oil shares the dose-related effects and not the form's three
Our brand: the worked example on this page
Futuro Labs Omega 3 Fish Oil
- 17p a day
- 90 softgels, 1 softgel daily
- Lab tested
- Made in the UK
A natural triglyceride-form oil, which shares the dose effects at its dose and none of the form's three: Futuro Labs Omega 3 Fish Oil on Amazon UK, 1 softgel with a meal, 180mg EPA and 120mg DHA, lab-tested purity, 90 for £14.99 at 17p. Full label breakdown. Whether ethyl ester is safe is on the ethyl ester safety page; the forms compared on the forms page.
The prescription leaflet read in order, common, less common, warned and noted
The potential side effects of taking omega-3 ethyl esters, and the variants asking about omega-3-acid ethyl esters, are answered best by reading the prescription leaflet, because omega-3-acid ethyl esters is the name of the prescription product, a gram of ethyl ester per capsule at two to four grams a day for high triglycerides, and its summary of product characteristics is the most honest side-effect list any omega-3 has, being written by a regulator rather than a shelf. Common, in the leaflet's sense of more than one in a hundred: dyspepsia, an upper stomach discomfort after the dose, and nausea, the two effects of a gram of oil arriving in a stomach at once. Less common: taste disturbance, a fishy or altered taste that lasts, belching, the repeating that every fish oil page on this site addresses, abdominal pain and loose stools, the gut's complaint at two grams and up that the signs page ranks first, the leaflet grading these below the common pair because the prescription is taken with meals and the dose is titrated. Warned: a note that bleeding time may be prolonged at high doses in patients on anticoagulants, so that a patient on warfarin or a newer anticoagulant has their clotting monitored, the platelet effect that the outcome trials found minor and that a prescriber watches at four grams. Noted on the lipid panel: a small rise in LDL cholesterol at the four-gram dose, the trade the triglyceride-lowering literature records for any DHA-containing preparation and that the prescriber accepts against a large triglyceride fall. And, in the later editions of the leaflet, the atrial fibrillation signal from the outcome trials, added once the meta-analyses found the dose-related rhythm risk most evident at four grams, so that a prescriber now takes a rhythm history before the four-gram dose, the omega-3-acid ethyl esters leaflet's list.
The form's own three, which a shelf ethyl ester shares and a triglyceride oil does not, the reading for each reader, and the effects filed
The leaflet lists the effects of the dose; the form adds three of its own, which apply to a shelf ethyl ester oil as much as to the prescription, and which a triglyceride oil does not share. Poor absorption without a fatty meal: an ethyl ester's fatty acids are bound to ethanol rather than to glycerol, the pancreatic lipase that digests it works poorly on the ethyl bond without the bile and fat of a meal to help, and the absorption of an ethyl ester taken fasted falls to a fraction of the same oil taken with a fatty meal, the ethyl ester stability and absorption literature's finding, so a reader who takes an ethyl ester on an empty stomach has a side effect the leaflet does not list, which is a dose that mostly did not arrive. Worse reflux for many users: users widely report that an ethyl ester repeats and refluxes worse than a triglyceride oil at the same dose, the free ethyl backbone being suspected, which is why the burp pages' fourth question is whether the oil is an unstated form and why a stated triglyceride form is the fix at that step. Faster oxidation on the shelf: an ethyl ester oxidises more readily than a triglyceride oil once the tub is opened, the ethyl bond being less stable, so an opened ethyl ester goes rancid sooner, and rancid oil brings the all-day repeating and the aldehydes that the oxidised-oil pages describe, a side effect of storage rather than of swallowing. The reading for each reader: a patient on the prescription has the leaflet's list, a prescriber watching the panel, the rhythm and the clotting, and the form's three managed by taking it with meals and keeping the tub closed; a shelf reader on an ethyl ester fish oil, which is most of the cheap concentrate shelf, has the dose effects at whatever dose they have reached and the form's three whether or not the label admits the form, with a triglyceride oil as the answer to the three and the dose as the answer to the rest. The effects filed: the leaflet's common dyspepsia and nausea, its less common taste, belching, pain and loose stools, its bleeding warning, its LDL note and its rhythm note, and the form's own poor fasted absorption, worse reflux and faster oxidation, with the worked example being a natural triglyceride-form oil that shares the dose effects at its dose and none of the form's three, £14.99 for 90 at 17p.
| The source | The effect | The note |
|---|---|---|
| The leaflet, common | Dyspepsia; nausea | A gram of oil arriving at once; taken with meals |
| The leaflet, less common | Taste disturbance; belching; abdominal pain; loose stools | The gut's complaint at two grams and up |
| The leaflet, warned | Prolonged bleeding time at high doses with anticoagulants | Clotting monitored; the clinician told |
| The leaflet, noted | A small LDL rise at four grams; the atrial fibrillation signal | A lipid panel; a rhythm history before four grams |
| The form, one and two | Poor absorption fasted; worse reflux for many users | A fatty meal; a triglyceride form as the fix |
| The form, three | Faster oxidation once opened | A closed tub, cool and dark, finished within months |
The verdict, a regulator's list for the dose and three more for the form, none of which a triglyceride oil shares
What are the potential side effects of taking omega-3 ethyl esters: read off the prescription leaflet for omega-3-acid ethyl esters, common dyspepsia and nausea, less common taste disturbance, belching, abdominal pain and loose stools, a warning on prolonged bleeding time at high doses in patients on anticoagulants, a small rise in LDL cholesterol at the four-gram dose and, in later editions, the atrial fibrillation signal from the outcome trials, and then off the form itself, poor absorption without a fatty meal because the ethyl bond needs the fat to be digested, worse reflux for many users than a triglyceride oil, and faster oxidation once the tub is opened, three effects a shelf ethyl ester shares with the prescription and a triglyceride oil does not. A natural triglyceride-form oil: Futuro Labs Omega 3 Fish Oil, one softgel with a meal, 180mg EPA and 120mg DHA, lab-tested purity, 90 for £14.99 at 17p a day.
What to check on the label
- Read the leaflet's list as the dose's: dyspepsia, nausea, taste, belching, loose stools.
- Take the bleeding warning to the clinician if on an anticoagulant: clotting monitored.
- Expect the LDL note and the rhythm note at four grams: a prescriber's rung.
- Take any ethyl ester with a fatty meal: fasted, most of it does not arrive.
- Choose a triglyceride form for the reflux and the shelf life: the form's three fixed.
Our brand
The worked example: Futuro Labs Omega 3 Fish Oil
Futuro Labs Omega 3 Fish Oil: 1 softgel daily with food, 1000mg fish oil providing 180mg EPA and 120mg DHA (300mg combined), 90 softgels for £14.99, 17p a day, lab-tested purity, UK GMP made. Gelatin shell, so not vegetarian.
- Fish oil per softgel
- 1000mg
- EPA / DHA per softgel
- 180mg / 120mg (300mg combined)
- Serving
- 1 softgel a day
- Bottle
- 90 softgels, 90 days
- Price
- £14.99 (17p a day)
- Softgel
- mini softgel, no fishy taste
Questions people also ask
What are the side effects of omega-3-acid ethyl esters on prescription?
The leaflet's list: common dyspepsia and nausea, less common taste disturbance, belching, abdominal pain and loose stools, a warning that bleeding time may be prolonged at high doses in patients on anticoagulants, a small rise in LDL cholesterol at the four-gram dose and, in later editions, the atrial fibrillation signal from the outcome trials.
Are ethyl ester fish oils worse for side effects than triglyceride oils?
For three effects of the form, yes: an ethyl ester absorbs poorly without a fatty meal, refluxes and repeats worse for many users at the same dose, and oxidises faster once opened, while the dose-related effects, the gut, the bleeding time, the LDL and the rhythm signal, belong to the dose and are shared by any form at that dose.
Why must ethyl ester omega-3 be taken with food?
Because its fatty acids are bound to ethanol rather than glycerol and the lipase that digests the ethyl bond works poorly without the bile and fat of a meal, so an ethyl ester taken fasted is absorbed at a fraction of the same oil taken with a fatty meal, a dose that mostly did not arrive being the side effect the leaflet does not list.
Can omega-3 ethyl esters affect bleeding?
At high doses in patients on anticoagulants the leaflet warns that bleeding time may be prolonged, so clotting is monitored and the clinician told, the platelet effect being minor in the outcome trials and never an organ bleed, and a reader not on an anticoagulant having only easier bruising to notice at three grams and up.
Do the prescription side effects apply to a cheap ethyl ester fish oil from a shop?
At the same dose, yes, and the form's three apply regardless of dose: most cheap concentrate oils are ethyl esters whether or not the label says so, so a shop ethyl ester taken fasted absorbs poorly, refluxes worse for many and goes rancid sooner once opened, with a stated triglyceride form as the fix for all three.
Sources
- The summary of product characteristics for prescription omega-3-acid ethyl esters at a gram a capsule: common side effects of dyspepsia and nausea, less common taste disturbance, belching, abdominal pain and loose stools, a warning on prolonged bleeding time at high doses in patients on anticoagulants, a small rise in LDL cholesterol at the four-gram dose, and, in later editions, the atrial fibrillation signal from the outcome trials. https://www.medicines.org.uk/emc/search?q=omega-3-acid+ethyl+esters
- The ethyl ester fish oil literature: ethyl ester concentrates are the form of the licensed prescription omega-3 medicines, release only trace ethanol on digestion, absorb markedly better with a fatty meal than fasted, and are somewhat less oxidatively stable than triglyceride oils, so freshness matters more for them, with the polystyrene-cup test demonstrating solvent behaviour rather than any safety difference. PubMed record
- Meta-analytic evidence on omega-3 fatty acids and LDL cholesterol: triglyceride lowering is the consistent effect, with LDL unchanged or modestly raised, particularly with DHA-containing preparations. PubMed record
- Meta-analyses of cardiovascular outcome trials of marine omega-3: a dose-related increase in the risk of atrial fibrillation, most evident at doses of four grams a day and small or absent below one gram, a finding that sets the honest ceiling of high-dose omega-3 for a healthy adult. PubMed record